Peel the garlic cloves; cut them into 2 or 3, pieces, crush them, or chop them into smaller pieces.
Sauté the garlic with 3 tablespoons of oil in a dutch oven or cast iron frying pan until golden over medium heat.
Cut the hot chili pepper into halves, remove the seeds and add it to the pan.
Remove the garlic, if you have sliced it, and set it aside. You can also leave the garlic in the pan if you like a strong taste.
Mix the white bread and the parsley.
Toast at medium-high temperature until it becomes crispy.
Cook the spaghetti in plenty of boiling water until al dente or chewy. Drain it and reserve a cup of the pasta cooking liquid.
Pour the pasta into the skillet and stir constantly; add some pasta cooking liquid: the starch will make the sauce creamy, and it will evenly coat your spaghetti.
Sauté over high heat for a few minutes.
Garnish with toasted breadcrumbs with parsley and the garlic you have set aside. Serve hot.